freebsd kernel with SKQ
4addc9b82e
... otherwise zfs_getpages would mostly be called with one page at a time. It is expected that ZFS VOP_BMAP is only called from vnode_pager_haspage. Since ZFS files can have variable block sizes and also because we don't really know if any given blocks are consecutive, we can not really report any additional blocks behind or ahead of a given block. Since physical block numbers do not make sense for ZFS, we do not do any real translation and thus pass back blk = lblk. The net effect is that vnode_pager_haspage knows that the block exists and that the pages backed by the block can be accessed. vnode_pager_haspage may be wrong about the exact count of the pages backed by the block, because of a variable block size, which vnode_pager_haspage doesn't really know - it only knows max block size in a filesystem. So pages from multiple blocks can be passed to zfs_getpages, but that is expected and correctly handled. vnode_pager should not call zfs_bmap for any other reason, because ZFS implements VOP_PUTPAGES and thus vnode_pager_generic_getpages is not used. vfs_cluster code vfs_bio code should not be called for ZFS, because ZFS does not use buffer cache layer. Also, ZFS does not use vn_bmap_seekhole, it has its prviate mechanism for working with holes. The above list should cover all the current calls to VOP_BMAP. Reviewed by: kib MFC after: 6 weeks |
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bin | ||
cddl | ||
contrib | ||
crypto | ||
etc | ||
games | ||
gnu | ||
include | ||
kerberos5 | ||
lib | ||
libexec | ||
release | ||
rescue | ||
sbin | ||
secure | ||
share | ||
sys | ||
tools | ||
usr.bin | ||
usr.sbin | ||
COPYRIGHT | ||
LOCKS | ||
MAINTAINERS | ||
Makefile | ||
Makefile.inc1 | ||
ObsoleteFiles.inc | ||
README | ||
UPDATING |
This is the top level of the FreeBSD source directory. This file was last revised on: $FreeBSD$ For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information). The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree, the most commonly used one being ``world'', which rebuilds and installs everything in the FreeBSD system from the source tree except the kernel, the kernel-modules and the contents of /etc. The ``world'' target should only be used in cases where the source tree has not changed from the currently running version. See: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. The ``buildkernel'' and ``installkernel'' targets build and install the kernel and the modules (see below). Please see the top of the Makefile in this directory for more information on the standard build targets and compile-time flags. Building a kernel is a somewhat more involved process, documentation for which can be found at: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html And in the config(8) man page. Note: If you want to build and install the kernel with the ``buildkernel'' and ``installkernel'' targets, you might need to build world before. More information is available in the handbook. The sample kernel configuration files reside in the sys/<arch>/conf sub-directory (assuming that you've installed the kernel sources), the file named GENERIC being the one used to build your initial installation kernel. The file NOTES contains entries and documentation for all possible devices, not just those commonly used. It is the successor of the ancient LINT file, but in contrast to LINT, it is not buildable as a kernel but a pure reference and documentation file. Source Roadmap: --------------- bin System/user commands. cddl Various commands and libraries under the Common Development and Distribution License. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. games Amusements. gnu Various commands and libraries under the GNU Public License. Please see gnu/COPYING* for more information. include System include files. kerberos5 Kerberos5 (Heimdal) package. lib System libraries. libexec System daemons. release Release building Makefile & associated tools. rescue Build system for statically linked /rescue utilities. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. tools Utilities for regression testing and miscellaneous tasks. usr.bin User commands. usr.sbin System administration commands. For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html